Smaller file. Still clear? In this sample, the main message survives the smaller export at the size we checked.

A producer accepting a static creative has two questions to answer: does the file meet the delivery requirements, and can people read what matters in the intended placement? File size helps with the first. It cannot answer the second on its own.

One source, two exports

We built a neutral typographic poster in code and exported it twice. Both files are 1080 × 1350 JPEGs, with 4:4:4 colour sampling and baseline encoding. The source pixels and encoder stayed the same; only the quality setting changed.

  • Q90: 144,610 bytes, 144.6 kB

  • Q45: 59,324 bytes, 59.3 kB

Q45 uses 85,286 fewer bytes, a reduction of approximately 59%. These figures describe the complete source JPEGs. They do not describe the video, its cover, or the cropped details shown inside the illustrated presentation.

The robot is AI made. The test poster, exported files and measurements are our own constructed example, rather than a live campaign or client case.

What the preview shows

We viewed each original in a separate preview 360 px wide. The headline and CTA remained readable in both. The Q45 background looked flatter and more stepped.

We also compared the same detail at 3× magnification. Q45 showed more ringing and block like artifacts around the white CTA letters; Q90 had cleaner edges. That enlargement helps explain the difference, but it does not show that the smaller file’s main message is unreadable at the preview size.

The 360 px view is this comparison’s chosen preview. It is not a universal acceptance size or a test inside a social platform’s interface.

Make the decision for the placement

For this preview, Q45 preserves the main message and is a reasonable candidate if the other delivery requirements allow it. The cleaner enlarged crop is not, by itself, a reason to choose the larger file.

Another creative may contain smaller text or details that matter more to the message. These quality numbers therefore remain settings for this source and encoder, not a preset to copy into every export.

KSTUDIO’s production QA can help your team make that bounded choice: document the file properties, inspect the required information, and identify what still needs attention.

Check your file with Static Ad Check for file properties. It does not judge legibility. Then compare both complete exports at the intended display size: read the headline and action, use a matched enlargement to investigate differences, and return to the placement view to decide whether they matter.

Passing that visual check still does not establish ad network acceptance or campaign performance.